System of transportation



18,194 AM. 'EMBlmos Em. 2,339 257 SYSTEM OF TRANSPORTATION Filed Sept.1, 1942 3 Sheets-Sheet l INVENTORS ATTORNEY Jan. 18, 1944. U

A. M. EMBIRICOS ETAL SYSTEM OF TRANSPORTAT I011 Filed Sept. 1, 1942 3Sheets-Sheet 2 kZ z.

600 CYCLES e TE/WVSN/TTE/E I500 CYClES a r 519%? FOR 7" J 7' 17/ 50,960UP D0 W/V SPEED;

5 TEEE/A/G IDLE INTERMEDIATE FULL IDLE INTERMEDIKTE FULL IDLE IN ERMEDIAE FULL SHIP No.1. SHIP NO.2. SHIP No.3.

- MAs gR CONTROL STEER" SPEED (D Q Q Q Q Q 4, L 5 7 I OLE INTERMEDIATEFULL PORT STARBORRD UP DOWN IDLE INTERMEDIA E FULL 00 sum No.4. SHIPNo.5.

DLE I TERMEDIATE FULL IDLE INTERMEDIATE FULL I'DLIE INTERMEDIATE FULLSHIP No.6. SHIP N0. 7. SHIP NO.8.

ATTORN EY J A. M. EM BIRICOS EIAL 2,339,257 I SYSTEM OF TRANSPORTATION sSheets-Shee t 3 Filed Sept. 1, 1942 a R mm x mm um MN MN My INVENTORSANDRE MAR/.5 fflB/E/COS FEEDER/6K B. H/OODM/GETH ATTORNEY Patented Jan.18,1944 I umreo s'r 2,339,257 7 SYSTEM OF TRANSPORTATION ApplicationSeptember 1, 1942, Serial No. 456,902-- 20 Claims.

The primary purpose of the invention herein disclosed is to improve thesafety and economy.

or transportation of cargoes by water. It will be appreciated that this.is particularly important in time of war when the loss from torpedoesand mines becomes a significant factor.

Generally speaking there has been no change in the design andconstruction of cargo carryin vessels used in war from those used inpeace. The

superstructure and smoke-stacks oi the carrier units make them visibleto enemy craft at considerable distance and the individual units aresufficiently large to justify the expenditure of a torpedo to sink them.The difiiculty of, replacement of such vessels as fast as they are sunkpresents a very real problem, as is well known. The formation of convoysin the interest of common safety involves delay and necessarily slowsdown the speed to that of the slowest unit in the con- VOY.

The invention herein contemplates decided change in the design andcharacter of cargo carriers and in the manner of handling group orconvoy systems. For example in the case of ocean going tankers, insteadof units of, say, 10,000 tons dead weight, it is proposed to constructsmaller, barge-like units of, say, 2000 tons dead weight. The boats willbe of special design without superstructure and with the center ofgravity as low as possible so that under load the deck will bepractically flush with the surface. Diesel engines will be used so thatno smokestacks will be required and only the air intake of the enginesand the ventilation of the holds will be above the water at all times.

Since the boats run practically submerged it is not contemplated thatthere shall be any permanent crews aboard. Provision is therefore madein accordance with th invention to direct and control the boats from anaccompanying or escort boat such as a corvette or destroyer orsubmarine. These cargo boats may be so proportioned that five of themare equivalent in capacity to one conventionaltanker, and it is feasiblefor oneescort ship to convoy ten or even more of these cargo boats ofspecial design, arranged for example as a screen, half on one side andhalf on the other ofthe escort ship.

It is apparent that such cargo boats may be rapidly and cheaplyconstructed. They may be built from reinforced concrete and, as anexample, they may be 260 feet long and 36 feet beam and a depth of 2'7feet, but of large cargo dead weight capacity for such measurements. Aeries of ten to fifteen water-tight compartments will be incorporated inthe design so as to make it comparatively invulnerable to torpedoattack. The construction of carriers in these small and inexpensiveunits vastly increases the difficulty on the part of the enemy ineffectively raiding a convoy and the'damage that can be done by a singletorpedo is proportionately reduced Furthermore such a convoy presentslittle visibility to the enemy, the limit probably in no case exceedingtwo miles.

According to the invention the direction or control of the cargo boatswill be entirely automatic in the form of remote radio control from theescort ship. While in its broad aspects the invention is not limited toany particular form of radio control, the invention has beensuccessfully embodied and operated and will be illustrated in the formof a radio control system in which the local control circuits on thecargo boats are selectively picked out for operation by a selectorcircuit similar to that used for calling in radio telephony. Impulses ofaudio or above audio-frequency modulation from a two-tone oscillator aretransmitted over the radio channel, the sequence of impulses beingcontrolled by a mechanism-such as a telephone dial, and the selectorsetcn each cargo boat is connected to the audio output circuit of aradio receiver and respondsselectively according to the code dialed toset up a desired circuit. In this Way motors can be selectivelyenergized to perform any one of many local functions, such as steering,throttle control, the operation of automatic bilges or automatic alarmsystems. The energization of the motors will suitably be directionallycontrolled through a system of relays that will be selectively operatedby a master control relay that responds differently to the twomodulation impulses of different frequencies. Preferably the radiotransmitter will generate an ultra short wave capab e of eitheramplitude or frequency modulation so that the signal will not bedetected and the presence of the boats revealed to an enemy beyond aradius of approximately 25 to 30 miles. The code signals are subject toready change and will be frequently changed, for example at the end ofeach trip, so as to avoid the likelihood of the boats getting underunfriendly control by one who happened to have devices for receiving thespecial waves. p

The boats will be equipped with automatic steering mechanism forkeepingthe boats on a set course, and this will be controlled either bya suitable meridian seeking compass, such as a magnetic compass or by aradio compass or by both. Th remote radio control means will allow theoperator to enable or disable the radio compass at will. The radio loopwill seek a null P0817 tion with respect to the wave front of a signalfrom the transmitter, and relative motion between the boat and loopmakes a contact and energizes a motor that operates the rudder, and thuskeeps the boat on the set course. The course is set with relation to thedirection of the signal source as represented by the loop position andis determined by the relative setting of the contacts.

It is contemplated that the escort ship will have in its control room apanel for each escorted boat and a master control panel containing thecode dial and the necessary control buttons to effect the desiredoperations and to determine the direction or degree of control. Theindividual control panels will upon call to the respective boatsindicate the condition sought, for example, the throttle position andhence the speed. Means may also be provided to signal back to the escortship upon demand and to indicate on the panel the relative course of theboat. There may also be an emergency switch which in case of attack maybe employed to set in motion steering control members to turn the boatsvariously from their established courses and cause them to scatter. Whenthe danger is over it will be a simple matter to relocate the boats andrestore them to an orderly course. Meanwhile the armed escort boat willbe free to cope with the attacking enemy boat.

Other features of the invention will appear from the followingparticular description of the embodiment shown in the drawings andchosen for the purpose of illustration. This embodiment will not containmeans for performing all the functions above referred to but it isthought that the system as shown will be sumciently representative topresent the invention which will be hereinafter pointed out in claims.

Fig. 1 is a perspective representation of a flotilla embodying thesystem of this invention.

Fig. 2 is a diagram of the transmitting apparatus on the escort ship.

Fig. 3 is a diagram of a panel arrangement suitable for the boats shownin Fig. 1.

Fig. 4 is a schematic and wiring diagram of that portion of the systemon an escorted boat.

The escorted flotilla as shown in Fig. 1 is proceeding on a normalcourse in regular order, the

.relay I 3.

'aesaaw allel into each circuit. For example button 4 and button 5 willboth energize the oscillator for 1mpulses of 600 cycles, and button- 6and button 1 will both energize the oscillator for impulses of 1500cycles. With the transmitter operating these impulses go over theradiochannel as modulation impulses. The dial 8; as in atelephone ringer witha selector set, sends out the two impulses sequentially repeated as manytimes as the dial number indicates. For example if the number 4 isdialed, the two impulses will be repeated four times.

The radio receiving and selecting apparatus are shown diagrammaticallyin Fig. 4. The selector set is connected to the audio output circuit ofthe receiver 9, and it consists of a filter ID that separates the twoimpulses, a rectifier II for the current from the 600 cycle impulses, arectifier I2 for the current from the 1500 cycle impulses, and a biasedand polarized relay l3 oppositely pulsed by the two rectified currents.The biasing winding I 4 of relay I3 is energized from the 200 voltsupply through a voltage divider consisting of resistances l5 and IS.The relay I 3 controls the relation of movable contact I! with fixedcontacts l8 and I9. Current from rectifier H urges contact l1 in onedirection and current from rectifier l2 urgesit in the oppositedirection. The bias winding holds contact II in the last position towhich it is moved, until the opposing winding is energized and it isforced against the other contact.

Condenser 20 is alternately charged and discharged by the transfercontacts l8 and 19 of relay [3 when the relay is the dial 8. Thecharging current fiows from the 200' volt supply through aradio-frequency choke coil 2|, resistance 22 and contact is of Thedischarging current flows through contact I 8 and resistance 23 toground. This pulses relay 24 of the selector to operate the selectorcode wheel 25in the well known manner, this being the Western ElectricCompany No. BR selector and the construction and operation of the codewheel being shownin Patents Nos.

pulsed by operation of 1,200,095 and 1,343,256.

The code wheel 25 carries a contact which will make contact with any oneof a plurality of local,

eight cargo boats C being presumed to be under s the control of theescort ship E, shown as a corvette, through remote radio control asshown in the succeeding figures. The corvette is screened by the boatson either side, three on one side and three on the other, with two boatsin line with the corvette, one in front and one astern. The distancebetween the boats will be a matter of choice but in ordinary seas wouldordinarily be not less than a half mile in lateral spacing.

As shown, the decks of the cargo boats are prac-' tically awash andtherefore will not be visible at any considerable distance.

On the corvette is a radio transmission apparatus as shown in Fig. 2.The radio transmitter I is of a type to transmit from the antenna ,2ultra high frequency waves which will have a limited radius. Anoscillator 3 is known as a two-tone oscillator in that it producesimpulses of two frequencies, depending upon which of two oscillatorcircuits is closed. The frequencies for example are indicated as 600cycles and 1500 cycles, respectively. Two buttons are connected inparnormally open. contacts 29a and fixed contacts depending upon thecode number that is dialed. As shown there are three active contacts 26,21 and 28 that govern, respectively, relay solenoids 29, 30 and 3| eachof which controls two operating contacts and one holding contact.Solenoid 29 when energized closes two 29b, and also the holding contact290 the movable element of which is connected to the negative S e fPower line 32, the fixed element being connected with one side ofsolenoid 29 and the other side of the solenoid being connected inparallel with the positive side of the power line and with cut-outcontact 33 also engageable by the contact arm of wheel 25. Thereforewhen the code wheel is on contact 26 solenoid 29 is energized from lead34, solenoid 29, lead 35, contact 26 to ground. At the same time contact290 is made and the holding circuit comprising lead 3 t, solenoid 29,contact 29c and lead 36 is made. The code wheel may now leave contact 26and solenoid 29 will remain energized until contact 33 is dialedwhereupon solenoid 29 is shunted through leads 34 and 31, a resistance31a dead short circuit.

The energizing, holding and shunting circuits of relay solenoids 30 and3| may be similarly being provided to prevent atraced in connection withtheir respective code contacts 21 and 28. when the code wheeleontact armengages contact 21 currentfiows-from the positive side of supply 32through lead 88, resistance 88a, solenoid 30 and lead 88 to contact 21and thence to ground through the code wheel. Holding contact 300 is thusclosed completing an alternative circuit through lead 40. Relay contacts80a and 301) are thereuponclosed. when code contact 28 is engaged by thecode wheel contact solenoid 8| is energized through lead 38, resistance38b, solenoid 3 and lead M to contact 28 and thence to ground. Holdingcontact Sic is thus made closing an alternative circuit through lead 40.Also relay contacts 81a and 8") are closed. Lead 8! for contact 88connects with lead 38 at points to shunt the solenoids 30 and 3|.

Relays 29 and 30 control a course changing motor and relay 3| controls athrottle operating motor, as will be described. Relay 29 functions withan automatic radio compass or direction finder which is self 'sufilcientto determine the direction of change of course, but a reversing switchcoacts with the contacts of relays 30 and 3! to determine in oneinstance the direction 01 change of course and in the other instance thedirection of throttle control.

This reversing switch consists of reversing contact element 62 connectedby lead 63 to the positive side of the line, and fixed contact elementsI 82a and 52b. Contact element s2 is the pivoted armature of polarizedrelay it that is wired in parallel with the polarizingwindings oi. relayit. Winding Ma is energized by the rectifier current from the 600 cyclefrequency impulses, and the reverse winding ass is energized from the1500 cycle impulses. Thereforewhen the oscillator 3 is caused to emit600 cyclefrequency impulses armature 52 will close the reversing switchcontacts in one direction, and

when 1500 cycle impulses are transmitted over the radio channel, thereversing switch will be oppositely closed. The armature 62 is springbiased toward the; center or open circuit position, so that when neitherpolarizing winding is energized'the contacts are open.

Having been set upon a definite course the cargo boats are equipped withautomatic means to hold them upon that course. This automatic steeringmeans shown schematically in Fig. 4 is of the type shown in Patents Nos.1,885,098, 2,112,490, 2,112,504 and 2,116,629. A photo-electric cell anda source of light therefor cooperate with a specially designed compasscard of a magnetic compass to selectively activate the circuit of thereversible steering motor.

This automatic pilot arrangement will briefly be described. The rudder(not shown) is selectively operated by hand through steering wheel 45 orby power through steering motor 46, de-

pending upon the condition of a clutch (not shown) which incidentallycontrols switch 31, the switch being open when the steering wheel clutchis engaged and closed when the clutch is disengaged.

The compass card 48 is gimbal mounted in the usual way and isconstructed so that by its the cardinal points of the compass. The lampand cell are carried by the compass head which is maintainedin zeroposition-by the motor 48. This motor is energized inzone direction whenfull light is falling upon the cell, in the opposite direction when nolight falls upon the cell, and is deenergized when the light intensityis intermediate, that is, when the light is half in-.

tercepted by the card.

When the operator disengages the clutch connection between the steeringwheel and rudder stock and thereby locks the steering wheel, that actcloses switch 41. This connects lamp 49 across the line throughresistance 5|. At the same time it energizes armature 52 and closes thecontacts of switch 58 which controls the circuit of motor 66. Switch 54is then closed which connects the photo-electric cell across the line inofi and both are attracted when the source of light is over a cut-outportion of the card so as to fall in full intensity upon the cell. Theswitches are urged outwardly by springs so that when the light is cutoff altogether the back contacts are engaged;

The back contacts control the circuit of motor relay solenoid 5? and thefront contacts control the circuit of motor relay solenoid 58. Theserelays operate reversing switches of motor 60 so that the armaturecircuit is connected across the line in one direction when solenoid'5'iisenergized and in the'other direction when solenoid 58 is energized. Afeed-back ts from the motor turns the compass head until the motor isdeenergized.

Hence it will be understood that if for some reason the boat wanders ofiits set course, it moves the compass head with respect to the card andenergizes the motor at one way or the other which turns the rudder andat the same time turns the compass head back to zero position. Thereturn of the boat to its course causes the beam of light to pass on theother side of the cutofi edge and start to reverse the motor andstraighten up the rudder while the boat is'coming on to its course.Hunting is thus prevented and the result is that the boat comes smoothlyback on to its course without overrunning it and the feed-back 59 leavesthe head in the correct relation to the compass card.-

Differentially combined with this feed-back is a course changing motor00. The driven shaft 5! of this motor is connected by differential 62into the feed-back 59. Therefore any movement of the armature of motor60 moves the head of the compass and hence the line of the beam oflight. The motor $6 is thereby energized and turns the rudder to causethe ship to assume a new course. The feed-back during this rudderpositioning movement of motor db turns the compass head toward zeroposition at which the motor is cut off, but the turning movement of theship in response to the rudder tends to carry the compass head past thezero position and reverse motor 60 is made responsive to relays 38 and44. First the correct code number is dialed to actuate selector wheel 25to the position to make contact 21. This closes both contacts 38a and381:. Then contact 4 or 6 is closed, depending upon whether the courseis to be changed to port or starboard. This causes impulses of either600 or 1500 cycle frequency to be sent out, and relay 44 is therebycaused to move armature 42 on either contact 42a or 421). Thisdetermines which of the slow operating motor contact relays 63 or 64 isenergized. These control, respectively, the armatures 65 and 66 thatcooperate with both front and back contacts. They are biased to theirback contacts, as shown, and each on its forward contact closes thearmature circuit of motor 68 which includes the other back contact. Themotor is shown as series wound so as to be energized in one directionwhen relay 63 is energized and in the opposite direction .when relay 64is energized.

Let it be assumed that it is desired to change the course of an escortedboat to port. The operator on the escort ship first dials the codenumber of contact 21 and thus closes contacts 30a and 30b. He thenclosescontact 4 and causes the oscillator to'send out impulses of, say,600 cycles. This causes relay 44 to move armature on, say, contact 42a.This will energize relay 64 through lead 43, armature 42, contact 42a,lead 61, contact 3017, leads 68 and 69, solenoid 64, and

lead 18 to the other side of the line. Armature 66 is thus pulledagainst its front contact and motor 68 becomes energized through lead1|, field winding 12, lead 13, armature 66, lead 14, the brushes andarmature of the motor, lead 15, back contact of armature 65 and lead 18to the other side of the line.

tween the escort ship and the cargo boat which is being directed. Aradio signal is sent out from transmitter and a loop 88 will throughmeans disclosed in the said Moseley patent be automati- If switch 6 beclosed so as to transmit impulses H of 1500 cycles and move armature 42against contact 4212, then relay 63 is energized as follows: lead 43,contacts 42 and 82b, leads 16 and 11, contact 38a, leads 18 and 18,solenoid 63 and lead 18 to the other side of the line. This attractsarmature 65 and closes the circuit of motor 68 in the opposite directionas follows: lead 1|, field winding 12, lead 13, front contact ofarmature '65, lead 15, brushes and armature of the motor, lead 14,armature 66 together with its back contact, and lead 18 to the otherside of the line.

The consequent movement of motor 60 will be transmitted to the compasshead through diflferential 62 and the boat will assume a new course asabove explained. When the course changing motor has been caused tointroduce the proper value, the motor is stopped by dialing selectorwheel 25 so as to engage contact 33 and deenergize relay 38 and open thecontacts 38a and 38b. Relay 63 or relay 64, whichever one was energizedis thus deenergized, restoring its armature 'to the back contact andopening the motor circult.

The radio compass operates upon the principle of that disclosed, forexample, in the Moseley Patent No. 2,257,757, and may be used inconjunction with the automatic pilot above described to hold the boat ona definite course having a predetermined relation to its bearingrelative to the escort ship. The controlling principle of the radiocompass arises from the fact that a loop mounted to turn about avertical axis and tuned to a selected radio signal will automaticallyseek a position perpendicular to the incoming wave front. In this waythe loop can be caused to maintain a definite relation to the directionline becally positioned perpendicular to the wave front. The loop whichis thus relatively stabilized carries a contact 8| connected to thepositive side of the line 32 and positioned to coact with two segmentalcontacts 82 and 88. These contacts are connected by leads 84 and85,-respectively, to thefixed elements of contacts 29a andZ8b,respectlvely, the cooperative movable elements of which areconnected with leads 68 and 18, respectively.

The contacts 82 and 83 are set angularly in a selected position withrespect to the center line of the boat and the course is thusdetermined.

with respect to the facing of the loop 80. If contact 8| engages eithercontact 82 or contact 88 the course changing motor 68 is energized tointroduce a change of course and thereby turn the boat and with itcontacts 82, 83 until contact 8| is restored to neutral position Thus ifthe escorted boat is proceeding on a course under control of the radiocompass and it starts to wander from its course, promptly contact 8|engages contact 82 or 83, depending on the direction of the error. To beunder control of the radio compass contact 26 must have been dialed andrelay 29 must be energized. Contacts 29a and 291) are therefore closed.If contact 83 is engaged relay 63 is energized as follows: from the plusside of line 32 to contact 8|, contact 83, lead 85, contact 2%, lead 18,lead 19, winding 63 and lead 70 to the negative side of the line, Ifcontact 82 is engaged relay 64 is energized as follows: from the plusside of the line, contact 8|, contact 82, lead 84, contact 29a, lead 68,lead 68, winding 64 and lead 10 to the negative side of the line. Ineither case the course changing motor puts in the proper correction tobring the boat back on the original course. If desired means (not shown)such as a motor energized and controlled similarly to motor 60, may beprovided to change the angular setting of contacts 82, 83 by radioremote control. In this way the course of the escorted boat relative tothe direction of the incoming signal may be remotely changed.

As previously stated, relay 3| controls'the contacts of the controlrelays for the throttle operating motor. This motor is numbered 86 andits control relays, which are also slow operating are numbered 81 and88. Like relays 63 and 64, they control contacts that determine thedirection of energization of motor 86, and relay 44 determines which ofrelays 81 and 88 is energized when solenoid 3| is energized. A camarrangement operated by motor 86 controls series contacts in a holdingcircuit for relays 81 and 88 and will stop the motor when the nextthrottle position is reached, assuming of course that the circuitclosers for the control relays which were closed by radio remotecontrol, have been opened. Furthermore to prevent any uncertainty in theoperation of the throttle changing motor, each of relays 81 and 88control a back contact in the circuit of the other relay.

Assume that the operator dials contact 28 and then operates contact 5and so broadcasts impulses of 600 cycle frequency, so as to energizecoil 44a and attract armature 42' against contact 42a. Contacts 3|a and3|b are closed and relay winding 88 is energized as follows: from theplus side of line 32 through lead 43, contacts 42 and 42a, lead 89,contact 3|a, lead 88, back contact 9| of relay 81, lead 92, winding 88and 1ead'93 to the negative side of the line. This attracts armature 94and closes the motor circuit as follows: lead 95, field winding 96, lead91, contact 94, lead 98', brushes and armature of the motor, lead 99,back contact of armature I controlled by solenoid 81, and lead 93 to thenegative side of the line.

This will cause the motor to turn in a direction'to open the throttle,for example. If it be desired to reduce the throttle and turn the motorin the opposite direction, coil Mb is energized by pushing button I andbroadcasting impulses of 1500 cycles. Armature 52 will thereupon engagecontact MD. This will cause relay winding 81 to be energized as follows:from the positive side of the line through lead 43, contacts 42 and 42b,lead I6, contact 3Ib, lead iIlI, contact I02, lead I03, winding 81 andlead 93 to the negative side of the line.

Motor 86 operates cam I05, the edge of which is engaged by three camfollowers that are urged inwardly and will therefore drop into the lowpart of the cam. In so doing they individually break the holding circuitfor relays 81, 88 as will be described.

In the construction diagrammatically shown the motor also operates thethrottle I05 through the cam as a crank, by means of links I06, I0! andI08.

The relays 81 and 88 include holding contacts I09 and H0, respectively,connected in parallel in lead III that is connected to the idle speedcontact H2 that is on one of the cam followers. The fixed coactingcontact of the idle speed follower II2 is connected by lead H3 to thecam follower He that corresponds with the throttle position forintermediate speed. The third cam follower H5 is the full speed followerin that it drops into the lowpart of the cam when the throttle is infull speed position. The two fixed cooperating contacts of cam followerslit and H5 are connected by lead IIB, and the full speed cam follower H5is connected to the positive side of lin'e 32 by lead III.

From the above it will be seen that when conmember (not shown) thatwould be successively engaged by a contact on the compass head and tact28 has been dialed and the direction control relay 44 energized, one ofcontrol relays 8i and 88. will be energized and the motor '86 will startrunning. The cam follower that is on the low part of the cam and hasbroken its contact, will ride upon the cam and close its contact. Thiscompletes the holding circuit for the control re-. lay and the originalcircuit through contact 3m or 3lb will now be broken by dialing theshunting contact 33. The motor will continue to run until the next camfollower drops down into the cam depression which will break the holdingcircuit and deenergize the motor circuit by opening either contact 96 orI00. The result is that the motor will operate the throttle one step andwill then stop, and will not start again until contact 28 is againdialed.

Other dialed contacts may of course be provided for other operatingcircuits. For example extra contacts H8 and I I9 are shown which mayserve engine stopping and engine starting circuits.

It will also be understood that it is very possible to provide meanswhereby the escorted boat may be caused to signal to the escorting shipupon demand information as to various controlled conditions. For examplethe course of the escorted ship could be intermittently or upon demandsignaled to the escorting ship by means of short segmental contacts of acommutator would cause different radio signals to be emitted which wouldbe picked up and interpreted by the escort ship.

Similarly the three cam followers I I2, lit and 5 could closecontactsIlla, Uta and be, respectively, in their inward positions which could beutilized to indicate the throttle position and hence the speed back tothe escorting ship. The panel arrangement for this is indicated in Fig.3. There are eight panels, one for each ship, as well as the one mastercontrol panel with the dial and the buttons for selectively controllingthe several boats.

The eight panels are all alike. Each contains a key I20 which, forexample, would cause a signal to be transmitted that would operateselectively to close the transmitting circuit on the boat the panel ofwhich contains the key that is closed. Immediately a signal would comeback according to the throttle position and hence according to which camfollower is in. The signal sent out thereby could be variously indicatedon the panel. 'For example there may be three lights, as indicated,which will be selectively lighted according to the signal received andwill indicate the possible positions of the throttle.

It will be appreciated that through the design of the cargo boats andtheautomatic controls certain definite advantages are derived which haveboth war time and peace time value. In spite of the fact that concreteis heavier than steel and to that extent cuts down the cargo carryingcapacity, the design of the boat gives it considerably more dead weightcarrying capacity than a boat of orthodox design of the samemeasurements would have. A portion of the weight of the boats of thenovel design is put into the hull in the form of bulkheads to makewater-tight compartments, thereby achieving the dual purpose ofreinforcing the structure and making the boat practically unsinkable.

Moreover the design eliminates all requirements as to free board, crewaccommodations and superstructure. This is rendered possible by the factthat the boat is remotely controlled and therefore can run either with asmall, skeleton crew, or with no crew where the control is completelyautomatic.

Therefore not only is the cost of the boat as compared with orthodoxdesigns considerably reduced, but the cargo carrying capacity isincreased, in spite of the fact that it is built of concrete.

The construction herein diagrammatically represented and above describedis intended to be merely illustrative of the invention, and it ismanifest that the invention as pointed out in the appended claims may bevariously otherwise pulses, radio receiving apparatus on each cargo boattuned to receive the said impulses, a steering motor and a throttleoperating motor on each cargo boat, control means for each motor, andselector means on each cargo boat arranged selectively to energize thesaid motors and responsive selectively to the controlled impulses.

2. A system of transportation comprising an escort ship and a pluralityof escorted cargo boats forming a convoy, a radio transmitter on theescort ship adapted to transmit alternately impulses of two distinctivecharacteristics, code means for controlling the sequence of impulses, asteering motor and .a throttle operating motor on each cargo boat, localcontrol circuits for the motors, and selector means on each cargo boatresponsive selectively to code impulses to energize the local circuits.

3. A system of transportation comprising an escort ship and a pluralityof esorted cargo boats forming a convoy, a radio transmitter on the.escort ship adapted to transmit alternately impulses of two distinctivecharacteristics, code means for controlling the sequence of impulses) asteering motor and a throttle operating motor on each cargo boat; localcontrol circuits for the motors, a contact wheel on each cargo boatoperative selectively to energize the local circuits, and selector meansresponsive to the code impulses to actuate the contact wheel.

4. A system of transportation comprising an escort ship and a pluralityof escorted cargo boats forming a convoy, a radio transmitter on theescort ship adapted to transmit alternately impulses of two distinctivecharacteristics, code means for controlling the sequence of impulses, asteering motor and a throttle operating motor on each cargo boat, localcontrol circuits for the motors, and means on each cargo boat forcausing selective energization' of the local circuits, said meanscomprising a radio receiver and a selector including means to separatethe two frequency impulses received by theradio receiver, av relayoppositely pulsed by the two frequency impulses, and astep-by-stepcontact wheel controlling the local circuits and actuatedone step by each double impulse of the relay.

5. A system of transportation comprising an escort ship and a pluralityof escorted power driven cargo boats forming a convoy, a radiotransmitter onthe escort ship adapted to transmit impulses oftwodifferent frequencies, code means for controlling the sequence ofimpulses, two reversible electric motors on each cargo boat, oneconnected to operate the rudder and one arranged in control of thethrottle of the power means, an energizing circuit for each motorincluding a source of electric power, a pair of reversing contacts foreach motor circuit, radio receiving apparatus on each cargo boat tunedto receive said impulses, and selector means on each cargo boatresponsive selectively to the said impulses and arranged selectively incontrol of the reversing contacts.

6. A system of transportation comprising an escort ship and a pluralityof escorts-i power driven cargo boats forming a convoy, a radiotransmitter on the escort ship adapted to transmit impulses of twodifferent frequencies, code means for controlling the sequence ofimpulses, two reversible electric motors on each cargo boat, oneconnected to operate the rudder and one arranged in control of thethrottle of the power means, an energizing circuit for each motorincluding a source of electric power, a pair of reversing contacts foreach motor circuit, reversibly energizable solenoid means in control ofeach pair of reversing contacts, a circuit for each solenoid meansreversibly connectable with the source of electric power, a magneticallycontrolled switch in each solenoid circuit, radio receiving apparatus oneach cargo boat tuned to receive the said impulses,- and selector meanson each cargo boat responsive selectively to said impulses and arrangedselectively in control of the said switches.

7. A system of transportation comprising an escort ship and a pluralityof escorted power driven cargo boats forming a convoy, a radiotransmitter on the escort ship adapted to transmit impulses of twodifferent frequencies, code means for controlling the sequence ofimpulses, two reversible electric motors on each cargo boat, oneconnected to operate the rudder and one arranged in control of thethrottle of the power means, an energizing circuit for each motorincluding a source of electric power, a pair of reversing contacts foreach motor circuit, reversibly energizable solenoid means in control ofeach pair of reversing contacts, a circuit for each solenoid meansreversibly connectable with the source of electric power, a magneticallycontrolled switch in each solenoid circuit, radio receiving apparatus oneach cargo boat tuned to receive the said impulses, selector means oneach cargo boat responsive selectively to said impulses and arrangedselectively in control of the said switches, and relay means responsiveto the said impulses to connect the solenoid circuits selectively withthe source of electric power.

8. A system of transportation comprising an escort ship and a pluralityof escortedpower driven cargo boats forming aconvoy, a radio transmitteron the escort ship adapted to transmit impulses of two differentfrequencies, code means for controlling the sequence of impulses, tworeversible electric motors on each cargo boat, one connected to operatethe rudder and one arranged in control of the throttle of the powermeans, an energizing circuit for each motor including a source ofelectric power, a pair of reversing contacts for each motor circuit,reversibly energizable solenoid means in control of each pair ofreversing contacts, a circuit for each solenoid means reversiblyconnectable with the source of electric power, a magnetically controlledswitch in each solenoid circuit, radio receiving apparatus on'each cargoboat tuned to receive the said impulses, a selector including means toseparate the two impulses of diiferent frequencies and to rectify theinduced currents to direct currents, two relays each adapted to beoppositely pulsed by the two rectified currents, contacts controlled byone relay for oppositely connecting the solenoid circuits selectivelywith the source of electric power, and means selectively actuated by theother relay in response to the code impulses for selectively operatingthe switches.

9. A system of transportation comprising an escort ship and a pluralityof escorted power driven cargo boats forming a convoy, a radio transmitter on the escort ship adapted to transmit impulses of two difierentfrequencies, code means for controlling the sequence of impulses, tworeversible electric motors on each cargo boat, one

- oppositely ceiving apparatus on each cargo boat tuned to means toseparate the two impulses oi difierentfrequencies and to rectify theinduced currents to direct currents, two relays each adapted to bepulsed by the two rectified. currents, contacts controlled by one relayfor oppositely connecting the solenoid circuits selectively with thesource of electric power, and a step-by-step contact wheel actuatable inresponse to the code impulses of the other relay for selectivelyenergizing the magnetically controlled switches.

10. A system of transportation comprising an escort ship and at leastone escorted cargo boat, the cargo boat being designed with respect tothe relation of the center of gravity to the center of buoyance so thatit is normally substantially submerged in' the water with its decksubstantially flush with the surface, power means for propelling andsteering the cargo boat, controls for the power means, radiotransmitting means on the v escort ship, and receiving means on thecargo boat responsive to the radiant energy transmitted from the escortship for automatically operating the controls.

11. A system of transportation comprising an escort ship having atransmitter of radio impulses, dial means for controlling the sequenceof radio impulses according to a selected code, a plurality of cargoboats grouped about the escort ship and each having power steering andpropelling means, controls for the power means, radio receivingapparatus on each cargo boat tuned to receive the impulses transmittedfrom the escort ship, and a selector operated by the received impulsesand including a. step-by-step member arranged to actuate the controls.

12. A system of transportation comprising an escort ship having a radiotransmitter adapted to produce alternately and successively radiantimpulses of two different frequencies, code means for controlling thesequence of impulses, a plurality of cargo boats grouped about theescort ship and each having power steering and propelling means,controls for the power means, radio receiving apparatus on each cargoboat tuned to receive the impulses transmitted from the escort ship, aselector for each receiving apparatus including a relay pulsed by twosaid impulses \of different frequency, and a device actuated by t erelay and operated selectively according to c e to energize thecontrols. I

13. A system of transportation comprising an escort ship having a radiotransmitter adapted to produce alternately and successively radiantimtunable to a signal from the radiotransmitting apparatus, reversingcontacts in the relay circuit including a contact element positioned bythe loop, a solenoid, a circuit maker and breaker in the relay circuitcontrolled by the solenoid, radio receiving apparatus on the boatresponsive to radio impulses from the transmitting apparatus, andsolenoid energizing means actuated by the output of the receivingapparatus.

15. A system of transportation comprising an escort ship and an escortedcargo boat, a radio transmitting apparatus on the escort ship, a rudderoperating motor on'the cargo boat, control relays for the motor, anenergizing circuit for the relays, an automatic radio compass apparatuson the boat including a direction seeking loop and tunable to a signalfrom the radio transmitting apparatus, reversing contacts in the relaycircuit including a contact element positioned by the loop, a solenoid,a circuit maker and breaker in the relay circuit controlled by thesolenoid, radio receiving apparatus on the boat responsive to radioimpulses from the transmitting apparatus, a second circuit maker andbreaker connected in parallel with the first, a second solenoid incontrol of the second circuit maker and breaker, separate energizingcircuits for the two solenoids, and selector means actuated by theoutput of the receiving apparatus arranged in selective control of thetwo solenoid circuits.

16. A, system of transportation comprising an escort ship and anescorted cargo boat, a radio transmitter on the escort ship, anoscillator associated with the transmitter and adapted to generateimpulses of audio-frequency modulation, code means for controlling thesequence of the audio-frequency impulses, a rudder operating motor onthe cargo boat, control relays for the motor, an energizing circuit forthe relays, an automatic radio compass apparatus on the boat including adirection seeking loop and tunable to a signal from the radiotransmitter, a set of reversing contacts in the relay circuit includinga, contact element pdsitioned by the loop, two pairs of circuit makersand breakers connected in parallel in the relay circuit, those of onepair being in series with said reversing contacts, a

solenoid in control of each circuit maker and breaker, separateenergizing circuits for the two solenoids, a radio receiver on the cargoboat; and selector means actuated by the audio-frequency output of thereceiver and selectively responsive to the code impulses to control thetwo energizpulses of two different frequencies, code means forcontrolling the sequence of impulses, a plurality of cargo boats groupedabout the escort ship and each having power steering and propellingmeans, controls for the power means, radio receiving apparatus on eachcargo boat tuned to receive the impulses transmitted from the escortship, a selector for each receiving apparatus including a relay pulsedby two said impulses of difierent frequency, and a rotative step-by-stepdevice actuatable by the relay and efiective selectively in differentpositions to operate the controls.

14. A system of transportation comprising an escort ship and an escortedcargo boat, a radio transmitting apparatus on the escort ship, a rudderoperating motor on the cargo boat, control relays for the motor, anenergizing circuit for the relays, an automatic radio compass apparatuson the boat including a direction seeking loop and ing circuits.

1'7. A system of transportation comprising an escort ship and anescorted cargo boat, a radio transmitter on the escort ship, anoscillator associated with the transmitter and adapted to generateimpulses of audio-frequency modulation, code means for controlling thesequence of the audio-frequency impulses, a rudder operating motor onthe cargo boat, controlv relays for the motor, an energizing circuit forthe relays, an automatic radio compass apparatus on the boat including adirection seeking loop and tunable to a signal from the radiotransmitter, a set of reversing contacts in the relay circuit includinga contact element positioned by the loop, two pairs of circuit makersand breakers connected in parallel in the relay circuit, those .of onepair being in series with said reversing contacts, a solenoid in controlof each circuit maker and breaker, separate energizing circuits for thetwo solenoids, a radio receiver on the cargo boat, selector meansactuated by the audio-frequency output of the receiver and selectivelyresponsive tothe code impulses to control the two energizing circuits,9, second set of reversing contacts in series with the other pair ofcircuit makers and breakers, and relay means selectively responsive tothe received code impulses arranged in control of the said second set ofreversing contacts.

18. In a radio control escort system for ships including an escort shipand an escorted power boat, a radio transmitter on the escort ship, aradio receiver on the escorted boat adapted to detect waves emitted fromthe transmitter, a throttle operating motor on the power boat, a powercircuit for the motor including reversing contacts, relay means incontrol of the reversing contacts, a cam operated by the motor having aplurality of followers according to the number of throttle positions, anenergizing circuit for the relay means including the cam followers andcooperating contacts in series, each follower being arranged to engageits contact when on a high part of the cam and to leave its contact whenon a low part of the cam, a circuit maker and breaker in the relaycircuit, a solenoid in control of the circuit maker and breaker, anenergizing circuit for the solenoid, and control means for theenergizing circuit actuated by the output of the receiver.

19. In a radio control escort system for ships cluding an escort shipand an escorted power boat, an oscillator on the escort ship adapted togenerate radio impulses of two difierent frequencies, code means forcontrolling the sequence of the impulses, a throttle operating motor onthe cargo boat, a power ing reversing contacts, relay means in controlof the reversing contacts, a cam operated by the motor having aplurality of followers according to the number of throttle positions, anenergizing circuit for the relay means including the cam followers andcooperating contacts in series, each follower being arranged to engageits contact circuit for the motor includ- ,contact when on a low when ona high part of the cam and to leave its part oi the cam, a circuit makerand breaker in the relay circuit, a. solenoid in control of the circuitmaker and breaker, an. energizing circuit for the solenoid, and meansresponsive to the impulses of a sequence deter- 20. In a radio controlescort system for ships including an escort ship and'an escorted powerboat, an oscillator on the escort ship adapted to generate radioimpulses of two different frequencies, code means for controlling thesequence of the impulses, a throttle operating motor on the cargo boat,a power circuit for the motor including reversing contacts, relay meansin control of the reversing contacts, a cam operated by the motor havinga plurality of followers according to the number of throttle positions,an energizing circuit for the relay means including the cam followersand cooperating contacts in series, each follower being arranged toengage its contact when on a high part of the cam and to leave itscontact when on a low part of the cam, a circuit maker and breaker inthe relay circuit, a solenoid in control of the circuit maker andbreaker, an energizing circuit for the solenoid, means responsive to theimpulses of a sequence determined by the code means for controlling theen ergizing circuit, aset of reversing contacts in the relay circuit todetermine the direction of rotation of the motor, a solenoid in controlof the said set of reversing contacts having two windings active inopposite directions, and means for energizing one winding with theoutput of the receiver from impulses of one frequency and for energizingthe other winding with the output of the receiver from impulses of theother frequency. l

ANDRE MARIS EMBIRICOS. FREDERICK B. WOODWOR'I'H.

